Liquid fast moving consumer goods like shampoo, body wash, dish detergent or laundry detergent are usually sold in rigid plastic containers. These containers are produced in mass scale and usually follow a simple technology approach and design for economic reasons. The pack material is usually produced at a step prior to the filling of the container. The final sellable unit needs to be securely closed to ensure safe shipment without any leaking of the contained liquid. In most cases, the orifice used for filling at the manufacturing site is identical to, or at least close to, the orifice designed for the usage phase at the consumer's home. This does not normally apply to tubes, which are permanently sealed after the filling process while the intended consumer dispensing orifice is located at the opposite end to the filling position. Most standard bottled liquids in plastic containers are closed by a plastic cap (also referred as a closure or a closure assembly) that is attached to the container after the filling of the bottle at the manufacturer and is either screwed on, snapped on or sealed on. All caps snapped or sealed onto the bottle usually come with a moveable feature. Examples of caps that have a moveable feature are flip top or disc top closures. These caps allow consumers to open the bottle and dispense the product in a controlled way, while the cap's main part remains attached to the bottle.
The closure is desired to be designed in such a way so that, during the use of the product, it can be readily opened and closed by the consumer without requiring excessive amount of force. However, closures that can be readily opened using weak forces are occasionally accidentally and undesirably opened during product manufacturing, transportation and storage. Thus, there is a need for closures that (1) require increased amount of force for the initial opening and (2) require relatively low force for opening and closuring of the container after its initial opening and during the regular use by the consumer. In other words, the closure needs to provide tightness under manufacturing, transportation and storage conditions, while it allows the consumer of the product to readily open the container, dispense part of its content and close the container when needed. Part of the performance of the closure can be defined by these two fundamentally different requirements, that is, being tight before the initial opening and easy to open afterwards.